Installation Guide

 Installation  Testing  Maintenance Instructions
Proposition 65 Warning This product contains chemicals known to the State of California to
cause cancer or birth defects or other reproductive harm.
1
CAUTION: Do not pipe the relief valve
solidly to a oor drain, sewer or sump.
5. Install valve at least 12 inches above
surrounding ood level.
6. Always consult local codes for installation
methods, approvals and guidance.
OUTDOOR INSTALLATION
Model 975XL2 Backow Preventer may
be installed outdoors only if the device
is protected against freezing conditions.
Exposure to freezing conditions will result
in improper function or damage to the
device. The installation location must be
kept above 32°F. All the basic installation
instructions apply.
If installation is in a pit or vault, the Backow
Preventer must never be submerged in
water because this could cause a cross-
connection. Make sure that the pit or vault
always remains dry by providing ample
drainage.
INDOOR INSTALLATION
Indoor installation is preferred in areas that
are subject to freezing conditions. All the
basic installation instructions apply to such
installations.
PARALLEL INSTALLATION
Where uninterrupted service from a single
meter connection must be maintained, two
or more Backow Preventers may be con-
nected in parallel. All the basic installation
instructions apply to parallel installation. Be
sure to allow adequate room between the
units for testing and repair.
PLACING THE DEVICE IN SERVICE
After the installation of a Model 975XL2 has
been completed, place the unit in service
as follows:
975XL2 REDUCED PRESSURE PRINCIPLE
1. Start with both shut-off valves closed.
Slowly open the inlet shut-off valve until the
backow preventer is completely pressur-
ized. A brief discharge from the relief valve
may occur while the device is pressurizing.
The discharge should cease by the time the
shut-off valve is fully open. Device should
function properly. If the discharge does not
stop, refer to "MAINTENANCE INSTRUC-
TIONS" for repair procedures.
2. After the device has been pressurized,
vent all trapped air from both check valve
by slightly opening each of the four test
cocks.
3. Slowly open the downstream shut-off
valve. The Model 975XL2 Reduced Pres-
sure Principle Backow Preventer is now
in service.
4. If "spitting" or intermittent discharges
from the relief valve are noted, it could be
a result of pressure uctuation and/or a
water hammer condition in the system. If
such conditions exist, install water pres-
sure reducing valves or water hammer
shock arresters in compliance with industry
standards as needed.
5. After the Model 975XL2 has been pro-
perly installed, test the device (see "TEST
PROCEDURES"). If the device fails the
test, remove the rst and second check
valves and thoroughly ush the device. If
the relief valve fails to operate properly,
inspect the sensing passage for clogging
(see "MAINTENANCE INSTRUCTIONS").
Clean rubber seals of all debris and place
unit back in service.
CAUTION: Installation of Backow Pre-
venters must be performed by qualied,
licensed personnel. The installer should
be sure the proper device has been se-
lected for the particular installation. Faulty
installation could result in an improperly
functioning device.
ZURN WILKINS Model 975XL2 Reduced
Pressure Principle Backow Preventers
are for use on potable water lines where
a health hazard could exist if a backow
situation were to occur.
Proper performance is dependent upon
following these installation instructions and
prevailing governmental and industry stan-
dards and codes. Failure to do so, accord-
ing to ZURN WILKINS Limited Warranty "...
releases ZURN WILKINS of any liability that
it might otherwise have with respect to that
device." Such failure could also result in an
improperly functioning device.
Damage to the device could result wherever
water hammer and/or water thermal expan-
sion could create excessive line pressure.
Where this could occur, shock arresters
and/or pressure relief valves should be
installed downstream of the device.
1. Before installing a Model 975XL2 Back-
ow Preventer, ush the line thoroughly to
remove all debris, chips and other foreign
matter. If required, a strainer should be
placed upstream of the Backow Preventer.
CAUTION: Do not use a strainer in sel-
dom used emergency waterlines such
as re lines.
2. The Model 975XL2 must be installed
in a horizontal position to provide proper
operation of the relief valve.
3. Provide adequate space around the
installed unit so that the test cocks will be
accessible for testing and servicing.
4. If installation of a Model 975XL2 is in a
building, provide a suitable drain arrange-
ment to drain off spillage from the relief
valve. An air gap at least two times the pipe
diameter must be provided between the
relief valve and the drain piping to prevent
a cross-connection.
12" MIN
30" MAX
PROTECTIVE
ENCLOSURE
OPTIONAL
WATER METER
INLET SHUT-OFF
AIR GAP
DRAIN
DIRECTION OF FLOW
Model 975XL2
LEAD-FREE*
Reduced Pressure Principle Assembly (1/4" - 2")
*This product contains a weighted average lead content less than 0.25% for wetted surfaces.
*Certied to NSF/ANSI 61-G
®
®